Equation solvers, HP 41CV etc.

[Ángel Martin]

(12-03-2017 05:24 AM)Trond Wrote:  Thanks very much for the info!

Do the Math Pac and Advantage Pac use one of those keyboard overlays to reassign the keys?

Not really. These modules only have a basic SOLVE (in user code the MathPac and in MCODE the Advantage) to solve f(x)=0 conditions.

For an equation solver case this needs to be wrapped around more code to handle the variable selection and other management routines.

There are two "modern" implementations offering that, one is in the "Interchangeable Solutions" Module, based on the SandMath's FROOT in the same classic way as SOLVE - and the other is the "Equation Evaluation" from Mark Fleming - based on the Formula Evaluation ROM.
Both come with a basic equation library so you can use those examples to create your own equations.

You can find manuals and QRG for the first reference and the Formula Eval ROM here:
http://systemyde.com/hp41/documents.html

and more information on the second reference here: (scroll the list to the items in question)
http://www.hpmuseum.org/forum/thread-8795.html

There's another option provided by Greg McClure, he modified the "wrapper" in the Interchangeable Solutions to use the Formula Eval method - you can look into this one as well:
http://www.hpmuseum.org/forum/thread-8741.html